400 Id
 

I know it has been discussed before, but how can you ID a 400 from the outside? Arent there external weights on the flexplate or balancer? Something about the number of freeze plugs?

Thanks.

three freeze plugs instead of two . and a differnt balancer

I'll go along with the external balancing on the flex plate but, my 77 Blazer Chalet has the original 400 and has only two freeze plugs.

the freeze plug thing isnt 100% accurate all the time, but its been a while since I figured out the discrepency, so use caution...

but the balancer and flexplate are both weighted and are dead give away's... A chevy by the numbers sort of book (or a printout from mortec.com) would be an excellent identification tool also.

If the heads are off, look for the siamesed cylinders with the steam holes between bores..

pc

if its a small block with 3 freeze plugs each side of the block then it is definatly a 400. however, just because it only has 2 dosen't mean its not a 400, because there were some.

on the balancer, it is actualy a blancer, not a damper, so there is a section cut out of the outer diameter of the balancer to keep the assembly in balance. and there is a counter weight on the flexplate as well.

then there is always the casting numbers that you can look up